Cut-off tool



United States Patent O CUT-OFF TOOL George B. Johnson, 2776 Clear-water St., Los Angeles, Calif.

Filed July 1, 1951, Ser. No. 669,151

8 Claims. Cl. 29 -95 This invention relates to a 'cut-olf tool and has particular reference to a double bit, cut-off tool for making cut-offs on solid or hollow shafts which are rotated as by a lathe, automatic screw machine, or the like.

Cut-off tools are generally used in machining practice to cut off excess material from a work piece which has been machined to a desired configuration as in a lathe, automatic screw machine, or the like. Such tools are securely supported as in a tool holder of suitable design which is capable of selective transverse movement, relative to the bed stock of the lathe, to feed the tool into the workpiece as the latter is being rotated by the chuck of the lathe. The workpiece is severed from the original stock to complete the machining operation and provide a finished part. 7 I

It is preferable that an end thus secured is free from burrs and sharp edges, and it is advantageous if the cut-off operation includes a means for additionally automatically producing an end that is sutficiently chamfered to remove any burrs or sharp edges produced during the cut-off operation.

It is therefore an object of this invention to provide a new and improved cut-olf tool which provides a cutting 'edgeto make a cut-off on a shaft, or the like, and also provides means for automatically chamfering the end to remove any burrs or sharp edges produced during the Cut-off tools of the character described, are generally expensive to produce, and a large assortment of tools of variedsizes is required to be maintained by a machine operator, in order to meet the requirements of the various sizes of work pieces which the-operator encounters;

It is therefore a further object of this invention to provide a new and improved ent-off tool which incorporates in a unitary'piece, a plurality of cutting edges whichare suitable for work pieces of various sizes,

It is another object of this invention to provide ,an

elongated cut-otf'bladeof'uniform cross-section through- 7 out having a reinforcing rib extending therealong pro vided with a finish cutting surface positioned -to-finish cut the rim of thestock as 'anfincident to *the final stage'of the cut-offoperationandMhich' blade can be sharpened repeatedly until substantially the entire blade has been consumed in use; i T u I A still further object of this'invention is'to provide anew: and" improved cutting toolof the character 'described in which the means for chamfering the cut-off end. of theworkpi'ece may include various shapes and formsto result in desiredchamfer configuration. 17

I "A further objectrof this invention'is to provide a cutting tool as described which provides clearance recesses therefof prior methods and devices heretofore intended to accomplish generally similar purposes, i.e., for making cut-offs on workpieces as a final step in machining operations.

These and other objects of this invention will be more readily apparent to one skilled in the art, from the following detailed description of the drawings, and appended claims.

In the drawings:

Figure 1 is a perspective view in elevation, illustrating the cut-off tool,'in accordance with this invention, in a position relative to a shaft to be cut off;

Figure 2 is an enlarged fragmentary view in elevation as seen on the lines 2-2 of Figure 1, illustrating the starting position of the cut-oif tool relative to the shaft;

Figure 3 is an enlarged fragmentary view, similar to Figure 2, illustrating the position of the cut-olf tool relative to the shaft at the end of the cut-off operation;

Figure 4 is an enlarged view in elevation as seen on a line 4-4 of Figure 2 illustrating the relationship of the cut-off tool to a shaft as seen from the underside of said parts;

Figure 5 is an enlarged view, in elevation, similar to Figure 4,'illustrating the chamfering position of the cutoff tool relative to the shaft,

Figure 6 is an enlarged view, in elevation, illustrating the application of the cut-off tool relative to a shaft which is rotating in a direction opposite to that shown in Figure 2.

Figure 7 is an enlarged view in elevation, similar to Figure 5, showing a modified embodiment of the cut-off tool in accordance with this invention;

.' 'Figure 8 is an enlargedview in elevation, similar to Figure 5, showing another modified embodiment of the cut-off tool; and 4 Figure 9 is an enlarged end view in elevation'of a further modified embodiment of the invention.

Referring more particularly to the drawings, there is shown, by way of illustration but not of limitation, a cutoff tool indicated generally by the numeral 10, which includesan elongated body 11, having a substantially rectangular configuration.

L The body 11 includes a pair of cutters 12 and 13 extending parallel to one another for the full length of the body. 1; It is to be understood that the body 11 may originate in a shorter form than illustrated, however,

an e

it 'is preferably provided with a length suflicient to pro- The ridge 22 which substantially enhances the rigidity of the-tool includes a substantially flat outer surface 26 and a pair ofsloped surfaces 23 and 24 to form the aforementioneddouble-bevel. v I

The sloped faces 17, 18, and edges 14, 16, form clear ancerecesses fonthe material encountered by the cut-off tool when presented to the workpiece, indicated at 27, to

. prevent over-heating of the tool bit or galling pr scratchin for more: elficient cutting and chamfering operationsf t Yet' 'another object of this invention is to provide "a new and improved cut-off tool which may be'fed into in :the machiningsop'eration. .4

the' workpiece (tangentially for greatest advantage A gen'eral object of-tthisinventiodistofpro'vide' 'a and improvedcut-ofi overcomes disadvantagei ing of the surface .of the workpiece during the cut-off operation. Additional clearance cut-outs are provided in V-shaped'form at the ends 28, 29 ofthebody llato prevent accumulation of material at these points during the.

cut-off operation. 5 I

' The bevelededgej14, the recessed face 1'17 and the cut away'end 28,;form a sharpened point- 31 to facilitate bit- 1 ing stthe 'tool lll into" the workpiece 27. Additional the remaining corners of the body to provide a plurality" of discrete sharpened and pointed cutters on the unitary body 11. 7 a V n 'I'heridge 22rnay .be of any suitable configuration, as the flat beveled construction described, and surfaces 23, 24 are preferably spaced different distances fromfthe bevelededges 14, 16 to correspond to the radius: of two slightly diiferent diameter workpieces. Fdrexample; cutter, blade 12 and its associated chamfer forming surface 23 are suitable for cutting off a workpiece from stock of a smaller diameter than is cutter blade 13 and its associated chamfer forming surface 24., Thus, it willlbe understood that each cutter blade and 'ehamfer forming surface areused most efliectively with stock'of a rather narrow diameter. 7 I r i 1 The backface 36 of the body 11 is preferably recessed as by] bellow grinding or the like to provide'clearancefor workpiece material in this area,-and may be provided with transverse or other serrations to facilitateclamping in a tool holder',.as indicated by the dotted lines 36'.'

As illustrated in Figures l throngh3, the cut-otfftoo 10 is positioned in a tool holder (not shown) at an acute angleto the vertical center line of the workpiece, and tangent thereto. As the workpiece 27 is rotated within the chuck ofthelathe (not shown),the tool 10 is advanced towards the workpiece 27 by conventional means incorporated in the lathe to cause the toolto bite into the workpiece-27 and begin the cut-ofi operation; Asthe tool bitis furtherradvancerl towards, the center. line .of the workpiece aposition of the tool bit is ultimatelyreachcd break or chamfer the,corner asfldesired w The :widthnfthc tool piece, i.e., the; distance between the;beveled sidey14 and the beveled; edge 23, may be of ;a;,dimensionsuitafble to-; the amount oif bevel;desired in the finishecl part:v an example, the width of the cutter 12 may be such that when the edge 19 is on or slightly past the axis of the workpiece 2f], the beveled edge 23 of the ridge 22 barely touches the peripheral edge of the cut-otfmade' to barely engageihe edge and remove any burrs .which may-be 7 presents. If a larger bevel is desired,.th e distance between the. aforementioned beveled 'facesnmay .be d ecreased; or

sented'from-theright side ofthe workpiece21 :td'pr'esent the point 33 in opposition to the Jrotation of the workpiece 27r 7 q t p V a V The cutter -13,- may;advantageously be formed with th'e beveled edge 16-of a diiferentdimensionalispacing'frdm the ridge22'to facilitate the cut-off of ashaft which isdifferent in size from th'e shaftcut otffby the blade l2, proyiding a more versatiletool which can be-usedto cut ofi more than onesizeofi shaft.- The cutters 12 and 1 3 may additionallybe of different dimensional thiclrnessgto',pr'cp videa more suitable tool for the various sized workpieees toj be cut; otf; As an example, as illustrated 'in Fig'; 9,

' one' cut'ter may 'be' thinner t han-the oth'erf fc'irus smaller workpiecesfandthe other cutter thicker-as re: largerworkpieces l I j The ridge22 of the-body llialso servesthe purpose-of reinforcing the body, to stiffen the body and prevent breakage thereof; By. the use ofa ridge, as d ri ed, a

-s'bmewhat'"'thinne butter can be rbvide' thf danger-"ofbreakageduejto a thinner cross-sec on, as 'is Fcott'mion tolprioiffart cut-ofi tools. The ridg ur-" appl ins a n n's an fa etdr flic u ing means normally incorporated in a tool holder such as iscomm'only usedin l'a'the's or the like. The'ri'dge' also serves as a means for retaining the tool in proper relationship with the workpiece as in cooperation with a suitable groove or slot provided in a tool holder.

As previously mentioned, the ridge 22 may take a variety of shapes and formsto provide a desired contour to the edge of the cut-ofi workpiece. As best seen in Figure 7, a modified formofcut-off' tool, designated by the numeral 10' is shown,-- wherein like parts are referred to by like numbers, and which includes a ridge 42 which has a fiat, or other, outer surface 43 and rounded or curved surfaces44; 45. A somewhat rounded appearance, as indicated at v46, is-givento the .edge of the workpiece 27' as a result.

Referring to Figure 8, another modified embodiment of the cut-off tool, designated by the numeral 10", is illustrated wherein -a ridge 52 isdisposed adjacent the beveled face14' and spaced at a greater distance'frdmthebeveled surface 16. Ifa rounded eonfigu'ration of thewbrrpieee 27" is desired afterthe cut offoperation, a halfvround configuration is given to the surface 53oflthelridg 52, and any desired configuration is incorporated intheopposed surface 54 of the.ridge 52.. Afterthe workpiece 27' isvcut off as by a cutter 56 of the cut-off tool, the to ol bitQc an bereversed.in thekto'ol holder topre s'ent the face 143, idemiea1to the iface 14. f theI first embodiment, tame wdrkpiec e 27 an d rourid the edgc 57 as by the curvedsuIfaceSBof theridge 15 2, Thus, it vwill be appar- .entffrm ,the ,.for'egoing description of the various forms of; ridges 2.2, 421a'ndl52, that. any, desired shape or configuration can be given to'the edge of the workpiece simultaneously with and as an;incident to. the completion .ofthe t-' 1. l s. 35 we te lr ne -h em {i nee-11 6mm in. theQforrii-of. Figure 8,;b'ut .tliexva'r'i oust shaped cutting and shaping edges can be varied and interchanged throughout the embodiments shown or de; scribed, withinthe skillofthe art and in the light of the instant teaching I i n v Also a'forming face 61, complementary tovthe surface 5 3,-for;ex ample,-can be formed on the opposite side-;36, shown' indotted 'outline; e.g;, in Figure 8.: I

Likewise, the ridg" 22, 42, and the like, are sometimes dvantageously formed-onboth-sides Ofthecuttingtml, PteiQr-ablY but not f necessarily, directly opposed to one another; s sh wn by y ty-example in' o edilinejs zzf.

42E,1 and;52, in;-Figures- -4-,- '7 and18 respectively; Thereby radii orotheredgesican be; formedon the cut-off part as well as 501111.116 stock, simultaneously in the .cut-offoperadon, andgthese-may, be ,difierent, if desired, for each cuttiugcdgeisorthat,'forexamplcafour differently shapedtcub ting bits 301". edges; can beaprovide'd; two (at each end a of the cutting toolr 1 a a V n Rcferringitofigure 9, 'th'ere isgshowna 'slightlymodified pf'cut-off 1001 10!", :wherein one. of the longitudinal cutte -8;. dicated by the 1nt meral ,70 -is appreciably, narrowenthan aniopposedgcutter 311.5 By usepf a zreinforcingzridge 62,;similar toridges 22,42 and 52,,a substantially thinnerwsection. is ;'possible for ltheicutter-70 toruse in making a cut-off on a shaft of a smaller ;diamcter,v-withut-breakage otahetoolri 1 v Ali impolt'tantjfeature of thiszinvntionras will, nowbe moreeclesrlytgundcrstoode, iszthe-l prbvi'sion-ot-iipargllel kmfimdintfl andicontinuousicutter iaces' .and-ridges,: which v ihetyv-shaped-;cutouts:s28,;.29,vthe componentiel'ements :of

theebodyggiving' the 'ztool an exceptionally longlylifehereto fotlmknownsto, the 1 3K472; i i v I; while! have herein shown cen;

hefittttcrsaare: automaticallysharpened merely shortening ceived to be the most desired .erribodir'nents ofxmy invien.

invention which is intended to comprehend any and all equivalent devices as comprehended in the following claims.

In the claims:

1. An article of manufacture comprising a cut-01f tool adapted to be rigidly clamped in the tool holder of a machine tool for cutting ofi a workpiece and simultaneously performing a finish cutting operation on the end of the stock as the tool completes the cut-off operation, said tool being of the type having a long straight blade of uniform cross-section from end to end thereof and having a beveled cut-off edge formed along its lateral edge, said blade being relieved along its opposite faces to provide clearance with the side walls of a cut as the tool is fed into the stock undergoing cutting, said blade being characterized by the provision of a reinforcing rib extending longitudinally thereof parallel to said lateral cut-off edge of the blade by a distance generally corresponding to the radius of the stock to be cut into individual pieces, the lateral edge of said rib adjacent said cut-off edge being a finish cutting edge adapted to engage and finish cut the end rim edge of the stock as said cut-ofi edge of the blade approaches and completes a workpiece cut-ofi operation.

2. An article of manufacture as defined in claim 1 characterized in that said reinforcing rib is spaced between the opposite lateral edges of said blade, and further characterized in that both later-a1 edges of said blade are beveled and effective as cut-off edges and in that the edge of said reinforcing rib adjacent each beveled edge cooperates therewith in providing a finish cutting edge.

3. An article of manufacture as defined in claim 1 characterized in that said blade is provided at its ends with oppositely-facing wide shallow V-shaped notches, both lateral edgm of said blade being spaced from the opposite sides of said reinforcing rib, and the opposite lateral edges each being contoured to provide a finish cutting edge each adapted to engage and finish cut the rim edge of the stock as the adjacent associated cut-ofi edge of the blade completes a workpiece cut-off operation.

4. An article as defined in claim 3 characterized in that the finish cutting edges of said reinforcing rib are spaced different distances from the associated cut-off edge whereby said blade is adapted for use with workpieces of different sizes.

5. An article as defined in claim 2 characterized in that said reinforcing rib and its finish cutting edges are offset to one side of the longitudinal axis of said blade thereby accommodating said blade for use in cut-ofi operations on workpieces of different diameter.

6. An article as defined in claim 5 characterized in that the face of said blade opposite said reinforcing rib is hollowground and in that the portions of said blade adjacent the opposite sides of said reinforcing rib are thinner than the portions adjacent the associated beveled cutting edges thereof.

7. An article as defined in claim 2 characterized in that said reinforcing rib is confined to one of the broad side faces of said blade.

8. An article as defined in claim 7 characterized in that the broad face of said blade on the opposite side thereof from said reinforcing rib is provided with serrations adapted to cooperate with the roughened surface of a tool holder clamping means in holding said blade anchored against displacement longitudinally of the blade in the holder.

References Cited in the file of this patent UNITED STATES PATENTS 169,913 Martin Nov. 16, 1875 641,997 Preston Jan. 23, 1900 1,223,438 Spencer Apr. 24, 1917 1,695,955 Frayer Dec. 18, 1928 1,701,980 Luers Feb. 12, 1929 1,835,958 Luers Dec. 8, 1931 1,855,971 Kilmer Apr. 26, 1932 2,335,570 Montgomery Nov. 30, 1943 2,370,273 Ulliman Feb. 27, 1945 2,679,679 Metzler June 1, 1954 

